An optical module includes a base which has a main surface and in which a mounting region and a driving region for moving the mounting region along a first direction parallel to the main surface are provided, a movable mirror which has a mirror surface having a positional relationship of intersecting the main surface and is mounted in the mounting region, a first fixed mirror which has a mirror surface having a positional relationship of intersecting the main surface and of which a position with respect to the base is fixed, and a beam splitter unit which constitutes a first interference optical system for measurement light together with the movable mirror and the first fixed mirror. The mirror surface of the movable mirror and the mirror surface of the first fixed mirror are directed to one side in the first direction.